THEFT DETERRENT SYSTEM Theft Warning Siren Circuit

DESCRIPTION

The theft warning siren has an internal battery. If the vehicle battery cable is disconnected or any of the communication lines are open, the theft warning siren detects this and sounds its siren.

Although the theft warning siren usually sounds by receiving a signal from the main body ECU (multiplex network body ECU), the theft warning siren can sound by its internal battery in case the vehicle battery cable is disconnected.

The main body ECU (multiplex network body ECU) sends an arming signal to the theft warning siren while transferring to the armed state, and it also sends a disarming signal to the siren while switching to the disarmed state. Also, the main body ECU (multiplex network body ECU) can cause the theft warning siren to sound by sending an alarm signal during the alarm sounding state.

WIRING DIAGRAM

A01GD5XE02

CAUTION / NOTICE / HINT

Note


  • If the theft warning siren assembly is replaced, refer to the Service Bulletin.

  • Inspect the fuses for circuits related to this system before performing the following inspection procedure.

  • When replacing the main body ECU (multiplex network body ECU), make sure to replace it with a new one.

PROCEDURE


  1. PERFORM ACTIVE TEST USING GTS (SECURITY HORN2)


    1. Connect the GTS to the DLC3.

    2. Turn the ignition switch to ON.

    3. Turn the GTS on.

    4. Enter the following menus: Body Electrical / Main Body / Active Test.

    5. According to the display on the GTS, perform the Active Test.


      Body Electrical > Main Body > Active Test
      Tester Display Measurement Item Control Range Diagnostic Note
      Security Horn2 Theft warning siren ON or OFF -

      Body Electrical > Main Body > Active Test
      Tester Display
      Security Horn2
      OK
      The theft warning siren assembly sounds and stops correctly when operated through the GTS.
      Result
      Proceed to
      OK
      NG

    OK

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here

    NG

  2. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN ASSEMBLY - BATTERY AND BODY GROUND)


    1. A01GBR0C02
      *a

      Front view of wire harness connector

      (to Theft Warning Siren Assembly)

      Disconnect the theft warning siren assembly connector.

    2. Measure the voltage according to the value(s) in the table below.

      Standard Voltage
      Tester Connection Condition Specified Condition
      M8-5 (+B) - Body ground Always 11 to 14 V

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      M8-2 (GND) - Body ground Always Below 1 Ω
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  3. CHECK HARNESS AND CONNECTOR (THEFT WARNING SIREN ASSEMBLY - MAIN BODY ECU [MULTIPLEX NETWORK BODY ECU])


    1. Disconnect the M8 theft warning siren assembly connector.

    2. Disconnect the G79 main body ECU (multiplex network body ECU) connector.

    3. Measure the resistance according to the value(s) in the table below.

      Standard Resistance
      Tester Connection Condition Specified Condition
      M8-4 (CONT) - G79-18 (SSCL) Always Below 1 Ω
      M8-4 (CONT) - Body ground Always 10 kΩ or higher
      G79-18 (SSCL) - Body ground Always 10 kΩ or higher
      Result
      Proceed to
      OK
      NG

    NG

    REPAIR OR REPLACE HARNESS OR CONNECTOR

    OK

  4. CHECK THEFT WARNING SIREN ASSEMBLY


    1. Temporarily replace the theft warning siren assembly with a new or normally functioning one.

      Tech Tips

      Refer to the Service Bulletin.

    2. Check the operation of the theft warning siren assembly function.

      OK
      Theft warning siren assembly function operates normally.
      Result
      Proceed to
      OK
      NG

    OK

    END (THEFT WARNING SIREN ASSEMBLY WAS DEFECTIVE)

    NG

    REPLACE MAIN BODY ECU (MULTIPLEX NETWORK BODY ECU) Click here